The invention relates to electrochemical generated gases and more specifically to a miniature, battery-like device for generating gases or as a power source or battery.
The use of electrochemically generated gases in fluid delivery is well known. Oxygen-driven fluid delivery, with oxygen being extracted from the air, has been described by Maget in the various U.S. Pat. Nos.: 4,687,423, 4,886,514, 4,902,278, 5,928,194, 5,938,640 and 6,383,165. Hydrogen-driven fluid delivery is exemplified by the Disetronic Infuser, a disposable syringe pump, which uses a galvanic cell as a hydrogen source.
In many applications, the rate of fluid delivery is of the order of a few microliters/hour over long periods of time, such as months. In U.S. Pat. No. 6,383,165, Maget describes such a delivery system which has been shown to operate at a constant delivery rate for about 4 months.
Many of these commercial applications are price-sensitive; such is the case of the long term release of pheromones in forestry and agriculture or the delivery of fragrances in the home environment. Therefore there is a need for economical, long-life, disposable gas generators.
In U.S. Pat. No. 6,387,228, Maget describes the electrochemical generation of carbon dioxide (CO2) and hydrogen (H2), based on the decomposition of organic acids, such as formic or oxalic acid. In the current invention, the inventors describe an extremely simple means to assemble and operate a miniature electrochemical gas generator, based on the decomposition of organic acids as described in '228, which meets the criteria for economy and longevity.
Such a generator is particularly well suited for the delivery of small quantities of liquids, such as pheromones, fragrances, insecticides, pesticides , or in general chemical agents, at extremely low flow rates.